Freedom 7 Shark Shield battery and replacement info (picture intense)

NowhereMan's thread (http://www.norcalkayakanglers.com/index.php?topic=96475.msg1082188#msg1082188) on using external power source to energize the Freedom 7 sparked my interest in learning more about the Shark Shield batteries. The thought of using an external power source is interesting, but I want to retain the freedom and convenience of being able to deploy the Shark Shield at any location on the kayak without the dependency on an external power source. A Shark Shield having a good condition battery should last long enough for a day trip.

The manufacturer claimed that the battery cannot be serviced or replaced. I find that hard to believe, so I had decided to find out more about their batteries and hopefully learn how to replace them. The main goal of this thread is to document what I've learned about the SS battery packs, and therefore understand whether they can be replaced.



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Warning...

Lithium batteries can be dangerous if not handled properly. Please do not attempt to build your own battery pack unless you know what you're dealing with. This thread is meant to provide information about the Freedom 7 batteries. In no way am I encouraging people to build and replace their own SS battery. The info provided in this thread is strictly for educational purposes only. It is not meant to be a DIY tutorial, and therefore I will deliberately skip the step-by-step instructions on building the battery pack. If you decide to build your own and have a specific question on the pack-building process, feel free to PM me.

I should also mention the following...
Warranty for the Freedom 7 is voided if you unscrew the pack. Ocean Guardian claims that the enclosure is sealed by using a special tool to torque down the two security screws. You and I would have no way to re-torque it to the factory specs. Therefore, waterproofing is not guaranteed once you open the enclosure. For kayaking use, I don't think it would affect anything. But if you use your Freedom 7 for diving, the chances are, the seal will not be able to withstand the pressure that manufacturer claims it could sustain. The only way I think you can regain the waterproofing is by applying glue/sealant to the gap surrounding the entire perimeter of the case.

In reality, old/dead batteries are not covered under the warranty anyway. Ocean Guardian would rather sell you a refurb unit for ~$350 I think.

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If you're reading this thread, the chances are you want to know whether the Freedom 7 battery can be replaced? The short answer is YES, but one would have to build the battery pack. Once you have a new pack, it's a matter of de-soldering/soldering a couple of wires to replace the pack for SS Freedom 7 version A and B. Version C actually has a 2-pin JST connector, so no soldering needed. I know of one online shop in Australia selling replacement batteries for the Freedom 7, but I could not figure out which version of Freedom 7 they support. The batteries they mentioned do not match any of the SS battery I came across. Also, they cost $140 + shipping, and another $20 if you mail them your SS to replace the battery for you.



There seems to be three different versions of Freedom 7... GU1000A, GU1000B, GU1000C.

GU1000A (clear case) uses 3 Sanyo UF103450P (https://industrial.panasonic.com/ww/products/pt/lithium-ion/models/UF103450P) in series (aka, 3s). Each cell is rated at 1880mah minimum and 2000mah max. The pack contains a small Battery Management System board to provide high/low voltage cutoff and short-circuit protection. I do not believe the BMS provides balanced charging because I've never seen a BMS in that small form factor providing balance charging function. When fully charged, the pack is ~12.6v. Full discharged at ~9.0v. The BMS makes sure of that. The capacity of the pack is 22.2 watt/hr at best.
(This picture comes from NowhereMan's thread, with permission to re-use here.)




GU1000B (blue case) contains 3 Panasonic UF103450PN in series (https://pdf1.alldatasheet.com/datasheet-pdf/view/597738/PANASONICBATTERY/UF103450PN.html). The cells are rated at 1880mah. It also has a BMS board similar to the one in GU1000A.

(This is the actual battery from my GU1000B.)


(plastic wrap removed...)


(exposing the backside of the BMS board...)




GU1000C (blue case) uses 2 Panasonic NCR18650BD cells rated at 3200mah each. The pack when fully charged is 8.4v. When depleted is ~6.0v. Capacity is 23.68 watt/hr according to specs.
(Interesting note. Although the 2 cell pack in the GU1000C is smaller than the other two, it contains more energy than the earlier versions. Battery technology had improved since a dozen years ago, and the newer Shark Shield took advantage of that.)
(This is the original battery pack from my GU1000C. Please ignore the single 18650 on the bottom left. It is there for size reference only.)


Please note, if you need a tool to unscrew the two security nuts to open the SS case, you can refer to the picture above. Look at how the screw driver had been modified by using an angle grinder. You can also try to bend the prongs of a fork to fit the security nuts.

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Putting together and testing a replacement 3s pack for the GU1000B/A...

Having seen what the original battery pack is made of, I'm fairly confident that I could build a replacement pack. The following describes my discoveries and test data. (Btw, my original GU1000B and GU1000C batteries are running in perfect condition. I don't actually need a new battery. I'm only doing this to satisfy my curiosity.)



So, I looked everywhere for those UF103450P/N cells. I was only able to find one place that sells these original cells in the 1000's. Other places sell OEM knockoffs, but I don't particularly enjoy dealing with knockoff cells. Even if I'm willing to go with no-name cells, they are 2-4 times more expensive than the alternatives which I'll go into next.

After taking measurements from the GU1000B (which should be the same as GU1000A), I was able to source some reliable batteries that would fit inside the enclosure with very minor tweaks. I had decided to try these Panasonic NCR18500A 2040mah lithium cells. I figured out that stacking three of these would fit inside the GU1000B and most likely the GU1000A as well. So, I bought six cells to test the capacity and fit, enough for 2 packs. First is the capacity test. They all exceeded their rated capacity of 2040mah. They also have a higher capacity than the UF103450P.


The 3s BMS that I tried is "HX-3S-A02". You can find it online easily.

This clip shows the testing of the 3s BMS low voltage cutoff happened at 9.56v. Too high. (Please ignore the batteries in this clip. I was testing the BMS using old batteries.)


Then I tested a different board where it cuts off at 8.3v, and another that cuts off at 7.8v. That translate into cutoff cell voltage around 2.76v and 2.6v, which is like 98-99% of the pack's capacity. I was a bit surprised by the inconsistency, but as long as they cutoff above 7.5v (3x 2.5v) there will be no issue.


I put together the 3s NCR18500A pack to see if it would fit inside the GU1000B and possibly GU1000A.




I then tested charging my 3s pack from the SS. It stopped at 12.57v [3x 4.19v]. Nice.


(And in order to fit the 3s pack inside the GU1000B, you would have to clip the plastic tabs (circled in red) with a flush cutter or dremel in out.)



(If you have model GU1000A, this is what you'll need to clip off. Photo by forum user Fish N' Chip. He stated... "I had to partially remove the circuit board slot and the larger posts in the bottom case. Mine didn’t have the small posts to remove.  I cut them down and used my plastic welder to make the bottom flush with the case or it would not seat properly.  The circuit board flex interfered with the longer supports and needed to go to the bottom of the case. Coaxed it all back together and fired it up.  Everything seems to work as it should.")


(and the SS would power up...)


Next is to test the cutoff and capacity of the 3s NCR18500A pack. The BMS cuts off at 8.3v, and the pack puts out "1989 mah". That's more than the original SS battery. (BMS and capacity test completed. Just need to properly wrap the pack.)


I ran the same test with the original SS pack. It has "1841 mah", which is 39 mah below the specs. That's not bad at all for a 5 yr old pack. This confirms the original pack is still in great shape.


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Putting together and testing a replacement 2s pack for the GU1000C...

As I mentioned earlier, the GU1000C uses 2x NCR18650BD in series to put out 8.4v fully charged. 18650 cells are very easy to acquire and work with. I sourced some Panasonic NCR18650GA 3450mah 10A cells. Bought six, enough to make 3 packs.

These NCR18650GA cells are reliable and very well received by hobbyists. Spot-welding the pack is a piece of cake. Testing the BMS and the pack takes some time. The 2s BMS I tested with is the "HX-2S-A10".

I verified that each of the cells meets or exceeds the rated 3450mah.


Next is the 2s BMS test. Short-circuit protection works, and it has auto-recovery.


Then tested the low-voltage cutoff. Happened around 6.0v, roughly at ~90% of the total pack capacity. This would work just fine.


And finally hooking up the pack with the GU1000C to make sure it would power up.


(Please note, the batteries in the above clips are not the actual batteries to be used in the new pack. I used old batteries while testing the BMS only.)

At this point, I'm ready to put together the 2s pack with the new Panasonic cells. This picture shows the 2 NCR18650GA spot-welded together with the BMS.



The capacity test of the pack shows "3118 mah" for the pack. Although the cells are capable of above 3450mah, the BMS cuts off the voltage at around 6.0v, leaving about 10% of energy still in the pack. This would help the pack maintain a longer lifespan.



Next, I wanted to know how my pack compares to the original pack/bms. So, I tested the capacity of the original 2s pack from the GU1000C.

The original pack has "3002 mah", which means my new 2s pack has 116 mah (1.2 watt/hr) more energy than the original pack. As long as my pack has more energy than the original I'm happy.


This is the new pack after it's been properly wrapped...





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Final thoughts...
I think I can safely say that the Freedom 7 battery can be replaced. The replacement batteries of my choice put out slightly more than the original battery packs. I feel the Panasonic cells are a good choice because they are reliable, predictable, and relatively safe. Although my batteries have a higher capacity rating, the full potential was not realized because of the buffer at both the top and bottom ends decided by the BMS'. But at least the new packs performed better than the original packs.


What's next? I would like to perform a runtime test of the SS on the water and see how much energy the SS consumes. In order words, how long does the pack last. I think that's what really matters.

I would also like to test out those UF103450P/N cells that I found in China websites. I think I'll order a set to build a pack and test it. I'm always wary of batteries sold in Chinese websites because you'd never know what you'll get. If they perform according to specs, it means you won't need to modify the enclosure of the GU1000A/B. Simply de-solder the old pack and solder in the new pack. Almost as simple as swapping the 2s pack for the GU1000C.

Since the GU1000A/B do not provide a way to show battery voltage, and knowing the voltage level of the pack could help you maintain the battery life, I'm planning to add a voltage meter inside the enclosure of the GU1000A/B. Just waiting for parts.


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With all that say, I have a few new battery packs for the Freedom 7. PM me if you need one. First come first served. $40 for the GU1000C, $60 for the GU1000A/B. This would help recoup my material and shipping costs. It took me 2-3hrs to build a 2s pack, and 4-5 hrs for the 3s pack, not to mention the time spent on testing. Each pack has been tested to work correctly, and exceeds the factory specs. If there's enough interest, I may produce a small batch of them in the future.

Hope this info is useful to someone.
--ernest


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Update : 09/14/2022


I tested those UF103450P/N cells from China (https://www.aliexpress.com/item/2251832767916373.html?spm=a2g0o.order_list.0.0.740e1802ft5lAs). They claim to be Panasonic cells with 2350 mah. After looking at them in my hand, I doubt they are genuine Panasonic cells. My expectations on these are cells are low, but I went ahead and put together a pack anyway and ran some tests. It turns out they do hold their advertised capacity, but I wouldn't be able to verify how well they'll hold up in a long run. I ran 5 cycles on these cells. They were pretty spot on with their claimed capacity. This pack has 25% more capacity than the one in my original GU1000B.

So, if you were to put together a pack like this, you wouldn't need to clip any tabs on the lower enclosure. It would be a drop-in replacement for your depleted SS battery pack for GU1000A/B.


Here's the pack I put together.






And here are some capacity tests.

Nice, but I wish you'd be a little more thorough next time...

But, seriously, there is a ton of great info here.

I still haven't given up on my old SS. I charged the battery pack, and reconnected it, and it gave me the same result as connecting an external power source. That is, the SS powers up, but flashes green, and produces no shock effect.

I would check the obvious first. The fact that your SS boots up and gives you the normal blinking pattern means the board thinks everything is okay, and is sensing for salt water. I would perform the following checks in order...

1) First check the continuity between the electrodes and the big copper plates inside the case. You should get 0 ohm or just a few tenths of an ohm at most. Make sure you check both of the electrodes. (I remember you mentioned you had a rusted wire that leads to the electrodes. This is highly suspected.)
2) Check the connection between the controller and the copper plates. Make sure the controller has good physical contact and is snuggly inserted, no wiggle.
3) Check the two big capacitors are being charged up. This is dangerous, so be careful. Check the voltage against the rating printed on the Cap. The voltage should be below but somewhat in the ballpark of the Cap's rated voltage. If they both charge up, they should be ready to fire the electrodes. If they're not charged up, look for physical damage against other components on the controller.

Wow, thanks for the detailed report. Do you know if it would be possible to connect another battery pack to the charging pins in order to increase runtime? I have the GU1000C unit. Mine only lasts 4-4.5 since new.

Great thread!  Thank you for taking the time to show all the info.  I wonder if there is an alternative to 3D print a custom external housing that can hold on unto the original case but host a new set of battery.   I might do that if mine starts to fail.

Wow, thanks for the detailed report. Do you know if it would be possible to connect another battery pack to the charging pins in order to increase runtime? I have the GU1000C unit. Mine only lasts 4-4.5 since new.

The charging pins are electronically isolated from the battery. They only go thru the charging circuit, and the SS doesn't operate while it is charging. However, I have an idea that may achieve what you're looking for. When my components arrive, I will take a look at the charging port. It might be possible.

Great thread!  Thank you for taking the time to show all the info.  I wonder if there is an alternative to 3D print a custom external housing that can hold on unto the original case but host a new set of battery.   I might do that if mine starts to fail.

If you're willing to compromise the waterproofness of the case, you can do a lot of things to it, including what you described.

this is very very cool

Are the photos loading for anyone else?  I seem to only view the video previews.

Are the photos loading for anyone else?  I seem to only view the video previews.

i see them all

Hah, think I figured out why they wont load for me.  Using my work computer, they block access to Dropbox, since they are our competitor.  I'll open it on a non-work laptop haha

Hah, think I figured out why they wont load for me.  Using my work computer, they block access to Dropbox, since they are our competitor.  I'll open it on a non-work laptop haha

Hey Al, what's up man. Nice to see you active again.

Dropbox is the only free file hosting platform that still allows you to embed images in web pages, if you know how. At least that's what I found so far.

Hah, think I figured out why they wont load for me.  Using my work computer, they block access to Dropbox, since they are our competitor.  I'll open it on a non-work laptop haha

Hey Al, what's up man. Nice to see you active again.

Dropbox is the only free file hosting platform that still allows you to embed images in web pages, if you know how. At least that's what I found so far.

I use imgur.com for hosting images that I use in forums.  It leaves a bit to be desired as an image hosting platform, but does the trick with the simple forum use case.

Good to know. It supports embedding? Seems they specialize in GIFs?

Good to know. It supports embedding? Seems they specialize in GIFs?

Yeah, ignore all the social aspects and other fluff.  I just use the New Post button to upload an image or multiple images.  By default they're in a "hidden" state.  Then I right click and copy image address and embed them in forum posts using:

Code: [Select]

[img]https://i.imgur.com/blah.jpg[/img]
Hope that helps!